The term “voice mail service” is herein used to mean a service to store digitized voice message from a sender into a memory accessible by a receiver and to take out document data from the sender in terms of voice message. A voice mail apparatus employed for such a voice mail service includes a memory provided in an information network. Storage regions of the memory are assigned to registered terminals, respectively.
According to a known voice mail apparatus, among voice mail users registered at the apparatus, a voice mail sender can send a voice mail to a voice mail receiver and the voice mail receiver can reply to the voice mail sender by calling the voice mail sender.